Occasionally I give talks about journalism to school students and ask them why printed editions of newspapers vary between 36, 48 or whatever pages. Their answer is always that the size of the edition depends on how much news has happened the previous day, whereas the calculation has traditionally depended on how much advertising has been sold or (often, in these hard times) how much of a loss the publisher can bear.

In broadcasting, there's a different dynamic: Newsnight is almost always given 50 minutes to fill. It can sometimes be longer – a 9/11 or Mandela death extension – but is never shorter. This sometimes results, Jeremy Paxman has told Radio Times, in there not being quite enough to justify the airtime. On such "slow new days", Paxo says, he sometimes feels like urging the viewers to go to bed.

The reason that this doesn't happen is that TV is a selling business and is as prone as any market trader to talking up the goods. On Sky Sports, for example, even if the Premiership title has been settled four games back or Australia have already won the Ashes, so-called "dead rubber" games still start with the presenters orgasmically proclaiming: "Welcome to the game that everyone is talking about!" An end-of-season match between two mid-league teams with nothing to play for was once hysterically declared to be "of vital importance to players competing for new contracts".

But the counter-argument to the Paxo view that viewers should be packed off upstairs if not much has happened is that strong news days do not automatically produce strong programmes. It's often on a day without major headlines that a programme can include a report from generally ignored parts of the world or a discussion with an original twist. Easy meat can make journalists lazy; sparse larders can encourage invention.

Online journalism should, in theory, make it easier to align news with the space that it's worth, although the infinity of cyberspace can also encourage reports to go on for too long.

On old-fashioned television, though, it's our good fortune that Paxman's natural temperament means that he is unlikely to resort to what a Sky Sports presenter would do on a slow Newsnight news day: "Hello and welcome to perhaps the most mouth-watering second reading of the Fisheries Bill that parliament has ever seen. It's no exaggeration to say that the future of the government may depend on what happens on these green benches today!"

The rock magazine launched in 1981 and celebrates a publishing milestone in issue 1,500 … AND in issue 1,501. Editor James McMahon has chosen some of his favourite covers from AC/DC on issue one to its 2013 anniversary issue